Avascular Necrosis

Avascular necrosis (AVN), also known as osteonecrosis, is the death of bone tissue caused from a deprivation of blood supply. This condition most often affects the hip joint, though other joints can be affected as well. Blood flow can be cut off due to a dislocated joint or fractured bone.

At first, one might not notice any symptoms from avascular necrosis. As it develops, you’ll notice pain when you put weight on the joint and eventually even when you’re lying down. It is important to receive medical intervention with AVN. The Joint Center at Orthopaedic Associates boasts one of the best teams of orthopaedic specialists in the area, with Paul Roettges, MD, who specializes in treating hips leading the team.

Causes

Avascular necrosis is caused by a break in blood flow to the bone, but the cause of the impaired blood supply is not always known. There are certain risk factors that could potentially raise your chances of developing AVN, though having these risk factors does not directly mean you will develop it.

Risk factors include:

• Heavy alcohol use – Drinking heavily can cause fatty substances to develop that block blood vessels
• Injury – If you sustain an injury that leaves your blood vessels damaged, it can lessen the blood flow
• Steroid use – It is not entirely understood why prolonged steroid use leads to avascular necrosis, but it is theorized that the steroids may interfere with the body’s ability to break down lipids (fatty substances)
• Preexisting condition – AVN has been found in conjunction with other conditions such as cancer, blood disorders like sickle cell disease, HIV, systemic lupus erythematosus (SLE), gout, rheumatoid arthritis, lupus, osteoarthritis, osteoporosis, Caisson disease, and Gaucher’s disease

Diagnosis and Treatment

A doctor will generally use an X-ray as the first attempt to test for avascular necrosis. An X-ray won’t pick up AVN if it’s in the early stages, though. If it is not detected through X-ray, your doctor may perform an MRI scan. MRIs provide the most acute information during the early stages of AVN, more so than an X-ray or CT and bone scans which are also sometimes used in diagnosing.

Nonsurgical treatments are usually introduced before surgery is seriously considered. Nonsurgical options include medications (NSAIDs for pain, blood thinners to reduce blood clots, or cholesterol lowering medication to help avoid fatty substances that restrict blood flow), reduced weight on the affected joint, exercises to improve range of motion, and electrical stimulation. These treatments are best in the early stages of AVN and while they can usually help with pain management, they are rarely a permanent solution.

There are four commonly utilized surgeries to alleviate the effects of avascular necrosis:

1. Core decompression – A removal of the inner cylinder of bone. This reduces pressure and improves blood flow. It is best used in the early stages of AVN.
2. Bone graft – A transplant of healthy bone from one part of the body to another. It is often performed in combination with a core decompression. Sometimes, it will be a vascular graft, meaning the surgeon will also include an artery and a vein to increase blood flow.
3. Osteotomy – Reshaping the bone to lessen stress of the affected joint. This is best for patients in the early stages of AVN with a small affected area.
4. Total joint replacement/arthroplasty – Once the joint is damaged beyond repair, a total joint replacement is the best choice. The destroyed joint is removed and replaced by an entirely artificial one.

It is best to receive a diagnosis and treatment for avascular necrosis as early as possible. Once you’ve been diagnosed, you can talk with an orthopaedic doctor to decide which treatments should be considered as options for your particular case. If you’d like to meet with one of our orthopaedic specialists, give us a call at 904-825-0540 or request an appointment online.